基于冲击的涡扇发动机退化建模与下发预测

Degradation Modeling and On-wing Time Prediction of Turbofan Engine Based on Shock Model

为解决多性能参数模型无法描述不同起飞推力下发动机性能退化的问题,利用单性能参数结合极端冲击模型描述起飞时发动机全功率运转对热端部件的热冲击影响,利用线性退化模型描述发动机自然退化过程,建立发动机性能可靠度退化模型。利用V2500发动机全寿命EGTM数据,结合最大似然估计给出性能可靠度表达式与模型参数,最后利用机队中同型V2500发动机非完整EGTM数据验证模型,预测下发时间,结果表明此模型预测下发时间和实际下发时间的误差小于3%,证明了模型的有效性。

To solve the problem that the model of multi performance parameters cannot express the engine degradation at different thrusts,the extreme shock model was used to describe the thermal shock effect of full-power takeoff on the hot-end components by using a single performance parameter for civil turbofan engines,and a linear degradation model was used to describe the normal deterio⁃ration process,the performance reliability degradation model of an engine was set up.With the engine V2500 full-life exhaust gas tem⁃perature margin(EGTM)data,the maximum likelihood estimation was used to create the engine specific performance reliability expres⁃sion and its parameters were estimated as well.The incomplete EGTM data of this engine in the same fleet was used to verify the model and the engine on-wing time was estimated.The result shows that the error between the predicted on-wing time and actual on-wing time is less than 3%,so the model is effective.